package com.src.xyzk_personal.EOL;

import java.util.Arrays;

public class DesUtil {
	private static String TAG = "DesUtil";
	private static boolean [][] K = new boolean[16][48];

	//初置换
	private static int [] IP = {
			58 , 50 , 42 , 34 , 26 , 18 , 10 ,  2 ,
			60 , 52 , 44 , 36 , 28 , 20 , 12 ,  4 ,
			62 , 54 , 46 , 38 , 30 , 22 , 14 ,  6 ,
			64 , 56 , 48 , 40 , 32 , 24 , 16 ,  8 ,
			57 , 49 , 41 , 33 , 25 , 17 ,  9 ,  1 ,
			59 , 51 , 43 , 35 , 27 , 19 , 11 ,  3 ,
			61 , 53 , 45 , 37 , 29 , 21 , 13 ,  5 ,
			63 , 55 , 47 , 39 , 31 , 23 , 15 ,  7};
	//末置换
	private static int [] FP = {
			40 ,  8 , 48 , 16 , 56 , 24 , 64 , 32 ,
			39 ,  7 , 47 , 15 , 55 , 23 , 63 , 31 ,
			38 ,  6 , 46 , 14 , 54 , 22 , 62 , 30 ,
			37 ,  5 , 45 , 13 , 53 , 21 , 61 , 29 ,
			36 ,  4 , 44 , 12 , 52 , 20 , 60 , 28 ,
			35 ,  3 , 43 , 11 , 51 , 19 , 59 , 27 ,
			34 ,  2 , 42 , 10 , 50 , 18 , 58 , 26 ,
			33 ,  1 , 41 ,  9 , 49 , 17 , 57 , 25};
	//密钥置换
	private static int [] KP = {
			57 , 49 , 41 , 33 , 25 , 17 ,  9 ,  1 ,
			58 , 50 , 42 , 34 , 26 , 18 , 10 ,  2 ,
			59 , 51 , 43 , 35 , 27 , 19 , 11 ,  3 ,
			60 , 52 , 44 , 36 , 63 , 55 , 47 , 39 ,
			31 , 23 , 15 ,  7 , 62 , 54 , 46 , 38 ,
			30 , 22 , 14 ,  6 , 61 , 53 , 45 , 37 ,
			29 , 21 , 13 ,  5 , 28 , 20 , 12 ,  4};
	//密钥位移
	private static int [] KM = {
			1 ,  1 ,  2 ,  2 ,  2 ,  2 ,  2 ,  2 ,
			1 ,  2 ,  2 ,  2 ,  2 ,  2 ,  2 ,  1};
	//压缩置换
	private static int [] CP = {
			14 , 17 , 11 , 24 ,  1 ,  5 ,  3 , 28 ,
			15 ,  6 , 21 , 10 , 23 , 19 , 12 ,  4 ,
			26 ,  8 , 16 ,  7 , 27 , 20 , 13 ,  2 ,
			41 , 52 , 31 , 37 , 47 , 55 , 30 , 40 ,
			51 , 45 , 33 , 48 , 44 , 49 , 39 , 56 ,
			34 , 53 , 46 , 42 , 50 , 36 , 29 , 32};
	//扩展置换
	private static int [] EP = {
			32 ,  1 ,  2 ,  3 ,  4 ,  5 ,  4 ,  5 ,
			6 ,  7 ,  8 ,  9 ,  8 ,  9 , 10 , 11 ,
			12 , 13 , 12 , 13 , 14 , 15 , 16 , 17 ,
			16 , 17 , 18 , 19 , 20 , 21 , 20 , 21 ,
			22 , 23 , 24 , 25 , 24 , 25 , 26 , 27 ,
			28 , 29 , 28 , 29 , 30 , 31 , 32 ,  1};
	//S盒
	private static int [][][] S_box = {
			//S1
			{{14,4,13,1,2,15,11,8,3,10,6,12,5,9,0,7},
					{0,15,7,4,14,2,13,1,10,6,12,11,9,5,3,8},
					{4,1,14,8,13,6,2,11,15,12,9,7,3,10,5,0},
					{15,12,8,2,4,9,1,7,5,11,3,14,10,0,6,13}},
			//S2
			{{15,1,8,14,6,11,3,4,9,7,2,13,12,0,5,10},
					{3,13,4,7,15,2,8,14,12,0,1,10,6,9,11,5},
					{0,14,7,11,10,4,13,1,5,8,12,6,9,3,2,15},
					{13,8,10,1,3,15,4,2,11,6,7,12,0,5,14,9}},
			//S3
			{{10,0,9,14,6,3,15,5,1,13,12,7,11,4,2,8},
					{13,7,0,9,3,4,6,10,2,8,5,14,12,11,15,1},
					{13,6,4,9,8,15,3,0,11,1,2,12,5,10,14,7},
					{1,10,13,0,6,9,8,7,4,15,14,3,11,5,2,12}},
			//S4
			{{7,13,14,3,0,6,9,10,1,2,8,5,11,12,4,15},
					{13,8,11,5,6,15,0,3,4,7,2,12,1,10,14,9},
					{10,6,9,0,12,11,7,13,15,1,3,14,5,2,8,4},
					{3,15,0,6,10,1,13,8,9,4,5,11,12,7,2,14}},
			//S5
			{{2,12,4,1,7,10,11,6,8,5,3,15,13,0,14,9},
					{14,11,2,12,4,7,13,1,5,0,15,10,3,9,8,6},
					{4,2,1,11,10,13,7,8,15,9,12,5,6,3,0,14},
					{11,8,12,7,1,14,2,13,6,15,0,9,10,4,5,3}},
			//S6
			{{12,1,10,15,9,2,6,8,0,13,3,4,14,7,5,11},
					{10,15,4,2,7,12,9,5,6,1,13,14,0,11,3,8},
					{9,14,15,5,2,8,12,3,7,0,4,10,1,13,11,6},
					{4,3,2,12,9,5,15,10,11,14,1,7,6,0,8,13}},
			//S7
			{{4,11,2,14,15,0,8,13,3,12,9,7,5,10,6,1},
					{13,0,11,7,4,9,1,10,14,3,5,12,2,15,8,6},
					{1,4,11,13,12,3,7,14,10,15,6,8,0,5,9,2},
					{6,11,13,8,1,4,10,7,9,5,0,15,14,2,3,12}},
			//S8
			{{13,2,8,4,6,15,11,1,10,9,3,14,5,0,12,7},
					{1,15,13,8,10,3,7,4,12,5,6,11,0,14,9,2},
					{7,11,4,1,9,12,14,2,0,6,10,13,15,3,5,8},
					{2,1,14,7,4,10,8,13,15,12,9,0,3,5,6,11}}};
	//P盒
	private static int [] PP = {
			16 ,  7 , 20 , 21 , 29 , 12 , 28 , 17 ,
			1 , 15 , 23 , 26 ,  5 , 18 , 31 , 10 ,
			2 ,  8 , 24 , 14 , 32 , 27 ,  3 ,  9 ,
			19 , 13 , 30 ,  6 , 22 , 11 ,  4 , 25};

	private static void Initial_Permutation(boolean[] pt)
	{
		boolean [] tmp = new boolean[64];
		for(int i = 0;i < 64;i++)
			tmp[i] = pt[IP[i]-1];
		System.arraycopy(tmp, 0, pt, 0, tmp.length);
		return ;
	}

	private static void Final_Permutation(boolean[] pt)
	{
		boolean [] tmp = new boolean[64];
		for(int i = 0;i < 64;i++)
			tmp[i] = pt[FP[i]-1];
		System.arraycopy(tmp, 0, pt, 0, tmp.length);
		return ;
	}

	private static void P_Box_Permutation(boolean[] x)
	{
		boolean [] tmp = new boolean[32];
		for(int i = 0;i < 32;i++)
			tmp[i] = x[PP[i]-1];
		System.arraycopy(tmp, 0, x, 0, tmp.length);
		return ;
	}

	private static void Generate_K(boolean [] SK)
	{
		boolean [] L = new boolean[60];
		boolean [] R = new boolean[60];
		int i,j,st;

		//Arrays.fill(K, false);
		for(i = 0; i < K.length; i ++)
			Arrays.fill(K[i], false);
		for(i = 0;i < 28;i++)
		{
			L[i+28] = L[i] = SK[KP[i]-1];
			R[i+28] = R[i] = SK[KP[i+28]-1];
		}
		st = 0;
		for(i = 0;i < 16;i++) {
			st += KM[i];
			for(j = 0;j < 48;j++)
				K[i][j] = (CP[j] < 28)?L[CP[j] + st - 1]:R[CP[j] - 29 + st];
		}
		return ;
	}

	private static void Work(boolean[] L,boolean [] R,boolean [] KEY,int cnt)
	{
		int [] X = new int[48];
		boolean [] RES = new boolean[32];
		Arrays.fill(RES, false);
		Arrays.fill(X, 0);

		int i,j,a,b,st,st2,tmp;

		for(i = 0;i < 48;i++)
			X[i] = (R[EP[i]-1] ^ KEY[i]) != false?1:0;

		for(i = 0;i < 8;i++) {

			st = i * 6;
			a = (X[st] << 1) + X[st + 5];
			b = (X[st + 1] << 3) + (X[st + 2] << 2) + (X[st + 3] << 1) + X[st + 4];
			tmp = S_box[i][a][b];
			st2 = i * 4;
			for(j = 0;j < 4;j++)
				RES[st2 + (3 - j)] |= ((tmp >> j)&1) > 0?true:false;
		}

		P_Box_Permutation(RES);

		for(i = 0;i < 32;i++)
			L[i] ^= RES[i];

		if (cnt == 15) return ;

		boolean [] temp = new boolean[32];

		System.arraycopy(L, 0, temp, 0, temp.length);
		System.arraycopy(R, 0, L, 0, temp.length);
		System.arraycopy(temp, 0, R, 0, temp.length);

		return ;
	}

	private static void DES_enc(byte [] txt,byte [] enc)
	{
		int i,j;
		boolean [] L = new boolean[32];
		boolean [] R = new boolean[32];
		boolean [] pt= new boolean[64];

		for(i = 0;i < 8;i++)
			for(j = 7;j >= 0;j--)
				pt[i * 8 + (7 - j)] = (((txt[i]&0xFF) >> j) & 1) > 0?true:false;

		Initial_Permutation(pt);

		for(i = 0;i < 32;i++)
		{
			L[i] = pt[i];
			R[i] = pt[i + 32];
		}

		for(i = 0;i < 16;i++)
			Work(L,R,K[i],i);

		for(i = 0;i < 32;i++)
		{
			pt[i] = L[i];
			pt[i + 32] = R[i];
		}


		Final_Permutation(pt);

		for(i = 0;i < 8;i++)
			for(j = 7;j >= 0;j--)
			{
				byte tt = (byte) (pt[i * 8 + (7 - j)] != false?1:0);
				enc[i] |= tt << j;
			}

		return ;
	}

	private static void DES_dec(byte []txt,byte []dec)
	{
		int i,j;
		boolean [] L = new boolean[32];
		boolean [] R = new boolean[32];
		boolean [] pt = new boolean[64];

		for(i = 0;i < 8;i++)
			for(j = 7;j >= 0;j--)
				pt[i * 8 + (7 - j)] = (((txt[i]&0xFF) >> j) & 1) > 0?true:false;

		Initial_Permutation(pt);

		for(i = 0;i < 32;i++)
		{
			L[i] = pt[i];
			R[i] = pt[i + 32];
		}

		for(i = 0;i < 16;i++)
			Work(L,R,K[15 - i],i);

		for(i = 0;i < 32;i++)
		{
			pt[i] = L[i];
			pt[i + 32] = R[i];
		}

		Final_Permutation(pt);

		for(i = 0;i < 8;i++)
			for(j = 7;j >= 0;j--)
			{
				byte tt = (byte) (pt[i * 8 + (7 - j)] != false?1:0);
				dec[i] |= tt << j;
			}

		return ;
	}
	//mode = 0 加密 =1 解密
	public static int DES(int mode,byte[] src,int len,byte[] out)
	{
		//if(len > out.length / 2) return;
		int outlen = 0;
		int i,j,addr = 0;
		int run_time = 0;
		run_time = len / 8;
		if((len % 8) > 0)
			run_time ++;
		byte [] v_in = new byte[10];
		byte [] v_out = new byte[10];
		Arrays.fill(v_in,  (byte) 0);
		Arrays.fill(v_out, (byte) 0);
		//sk init
		boolean [] sk = new boolean[64];
		String key_str = "12345678";
		byte [] key = key_str.getBytes();
		for(i = 0;i < 8;i++)
			for(j = 7;j >= 0;j--)
				sk[i * 8 + (7 - j)] = (((key[i]&0xFF) >> j) & 1) > 0?true:false;
		Generate_K(sk);
		for(i = 0; i < run_time; i++)
		{
			Arrays.fill(v_in,  (byte) 0x20);
			Arrays.fill(v_out, (byte) 0);
			if((addr + 8) <= len)
			{
				System.arraycopy(src, i * 8, v_in, 0, 8);
				addr += 8;
			}
			else
			{
				System.arraycopy(src, i * 8, v_in, 0, len - addr);
				addr = len;
			}

			//copy

			if(mode == 0)
				DES_enc(v_in,v_out);
			else
				DES_dec(v_in,v_out);
			System.arraycopy(v_out, 0, out, i*8, 8);
			outlen += 8;
		}
		return outlen;
	}

}
